MTC refers to data exchange between two entities without human interference, i.e., a dialog between two machines.
The number of MTC devices in an MTC system will be far more than that of terminals in existing Human to Human (H2H) communication. Massive data will be produced in communication among such a large number of MTC devices, and have to be transmitted through a communication network. Such communications among machines also require network side management. An existing wireless communication network becomes a most effective and promising information bearing transmission technology for MTC communication due to exemption for wiring and a wide coverage.
In future industry, MTC devices will be used in various businesses. There is a pressing need for a solution for processing massive data exchange produced by such a great number of MTC devices. To allow optimizing signaling/data transmission between a network side and an MTC device, an MTC device may keep only a signaling connection to a control plane of the network when the MTC device does not have to exchange data with a network, and establishes a data connection on a user plane only when the MTC device has to exchange data with the network side. In the way, when an MTC server requires an MTC device to report data, the MTC server has to trigger the MTC device first to wake up the MTC device before a data connection on a user plane can be established between the MTC device and the network.
At the same time, in order to avoid access of a network by massive MTC devices at the same time, thus overburdening or even paralyzing the network, a time control feature is required to control timing of access by an MTC device. A time window for communication of an MTC device is determined by both subscription information of the MTC device and a strategy of a local network operator. The time window for communication of each MTC device is set by the network, and the MTC device can access the network only in the time window for communication, thereby preventing network overload caused by simultaneous attempts of massive MTC devices to access a network.
In triggering an MTC device, an MTC server generates a request for triggering an MTC device and sends the request to a 3rd Generation Partnership Project (3GPP) network. When the MTC device has a time control feature, the 3GPP network not only has to verify if the MTC server is valid and authorized to trigger the MTC device, but also has to inquire about whether the MTC device is in a time window for communication set for the MTC device by the network. The MTC server may not send a trigger to the MTC device unless the MTC device is in the time window for communication.
As an MTC device will be forced to get detached from a network at the expiration of a communication window of the MTC device, when the MTC device is in an attached state, the MTC device must be in a period of the communication window. When the MTC device is in an unattached state, the MTC device may or may not be in a period of the communication window. An attached MTC device may be triggered in an existing trigger mode without the need of determining time control information of the MTC device. However, in triggering an unattached MTC device, the time control information of the MTC device has to be determined to improve a trigger efficiency. Currently, no method for triggering an unattached MTC device is proposed.